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P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
NEMO a status report
P. Piattelli Istituto Nazionale di Fisica Nucleare Laboratori Nazionali del Sud
2nd Roma International Conference on Astroparticle Physics Villa Mondragone, may 13-15 2009
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Outline
R&D activities • Site exploration • Preliminary design of a km3 detector
NEMO Phase-1 • Aims and objectives of the project • Results and lessons learned
NEMO Phase-2 • The Capo Passero shore and deep-sea infrastructures • Developments of the technologies for the telescope construction
Conclusions and prospects • The contribution of NEMO to the KM3NeT european consortium
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
NEMO: a brief history
R&D activity towards the km3 started in 1998
Search and characterization of an optimal deep-sea site
Feasibility study and definition of a preliminary project of the km3
Development of innovative technological solutions for the km3 • Low power electronics • Directionsl PMTs
Advanced R&D activities to validate the proposed technologies • Phase-1 and Phase-2 projects
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
The NEMO collaboration
INFN Bari, Bologna, Catania, Genova, LNF, LNS, Napoli, Pisa, Roma Università Bari, Bologna, Catania, Genova, Napoli, Pisa, Roma “La Sapienza”
CNR Istituto di Oceanografia Fisica, La Spezia Istituto di Biologia del Mare, Venezia Istituto Sperimentale Talassografico, Messina
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Istituto Nazionale di Oceanografia e Geofisica Sperimentale (OGS)
Istituto Superiore delle Comunicazioni e delle Tecnologie dell’Informazione (ISCTI)
More than 80 researchers from INFN and other italian institutes
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
The Capo Passero site
The Capo Passero deep-sea site has been proposed in january 2003 to ApPEC as a candidate for the km3 intallation
• Depths of more than 3500 m are reached at about 100 km distance from the shore
• Water optical properties are the best observed in the studied sites (La ≈ 70 m @ λ = 440 nm)
• Optical backgroung from bioluminescence is extremely low
• Stable water characteristics
• Deep sea water currents are low and stable (3 cm/s avg., 10 cm/s peak)
• Wide abyssal plain, far from the shelf break, allows for possible reconfigurations of the detector layout
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Seasonal dependence of optical properties
No seasonal dependence observed
Average values 2850÷3250 m
Absorption and attenuation lengths (for λ=440 nm)
The measured value of 30 kHz is compatible with pure 40K background
Data taken in collaboration with ANTARES Dead time: Fraction of time with
rate > 200 kHz
PMT: 10”
Thres: ~.5 SPE
Optical background
Absorption lenght values are compatible with optically pure sea water
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
km3 architecture: the NEMO proposal
Detector based on tower-like structures with horizontal extent Non homogenus distribution of sensors
Vertical sequence of “storeys” Structure packable for integration and deployment
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Seafloor layouts
84 towers
X (m)
Y(m
)
main EO cable main Junction Box
secondary JB
“tower”
91 towers
Several different seafloor layouts have been considered and simulated
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Sensibilità a sorgenti puntiformi
Sensitivity to a point like source (α = -2 and declination -60°) as a function of observation time
E2 d
Nν /d
Eν [s
-1 c
m-2
GeV
]
☼ average on all declinations of northern sky from Ahrens et al. Astr. Phys. 20(5) 2004 – 507-532
91 towers-20 storeys 127 towers – 20 storeys IceCube ☼
years Ratio IceCube/127 torri
Ratio IceCube/91torri
1 2.7 1.9
3 3.1 2.2
5 3.5 2.4
The geometry • 10” PMT • 6 PMT/floor • 180m distance between towers • 20 floors • 40m distance between floor • 10m bar length
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
NEMO Phase-1
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
NEMO Fase-1 25 km E offshore Catania 2000 m depth
TSS Frame
Buoy
Junction Box
e.o. connection
e.o. cable from shore
Shore laboratory, Port of Catania
e.o. cable 10 optical fibre, 6 conductors
NEMO mini-tower (4 floors, 16 OM)
Mini-Tower unfurled
300
m Junction Box
15 m
Mini-Tower compacted
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Deployment and connection
Connection in the frame Connection of the JB Connection of the Mini-Tower
Deployment of the Mini-Tower Deployment of the JB Phase-1 installed in december 2006 at the Catania Test Site (2000 m depth)
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Fully operative for 6 months (commissioning and data taking) Many critical items and solutions validated
• Concept of “tower” with horizontal extent • Deployment of a compact structure with unfurling on the seabed • Double containment pressure vessels • “All-data-to-shore” synchronous acquisition • Low power electronics • Calibration (time and position) techniques
Some technical problems encountered • Loss of buoyancy in the tower • Electro-optical penetrators in the Junction Box
JB problems solved by replacing the defective components JB redeployed in 2008 and presently working Five months of data analysed “Lessons learned” fundamental for further developments
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Scheme of the prototype tower
Fours floors Lenght 15 m Vertical spacing 40 m
16 Optical Modules with 10” PMT
Acoustic Positioning 2 hydrophones per floor 1 beacon on the tower base
Environmental instrumentation 1 compass + tiltmeter in each Floor Control Module CTD (Conductivity-Temperature-Depth) probe on floor 1 C* (attenuation length meter) on floor 2 ADCP (Acoustic Doppler Profiler (including compass) on floor 4
TBM
FPM
FPM
FCM
FCM FPM
FCM
FCM FPM
br
br
br
br
H H
OM OM CTD
AB
C*
ADCP
Tower Base
Floor 1
Floor 2
Floor 3
Floor 4
Buoy
HC
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Acoustic positioning system Distance H0-H1 measured on floor 2 during 6 hours (1 Feb h.17-23)
Each point is averaged in 300 s
Construction
14.25±0.01
AP measure
14.24±0.06
Accuracy better than the required 10 cm
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Background rates on PMTs
The average measured rates are about 80 kHz for PMTs on floors 2, 3 and 4
as expected from 40K decay plus a contribution
of diffuse bioluminescence
Floor 4
PMT
The instantaneous rate value is calculated by the Front-End board of the PMT averaging, in a time window of 1 µs, all the hits whose amplitude exceeds a given threshold equivalent to 0.3 spe.
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Atmospheric muon angular distribution
23-24 January, 2007:
LiveTime: 11.31 hours OnLine Trigger: ~6⋅107
OffLine Trigger (7 seeds): 184709 Reconstructed tracks: 2260 Selected tracks: 965
Azimuth
Likelihood
Distribution
Zenith
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Vertical muon intensity
Vertical Muon intensity as a function of depth from data recorded on 23-24 Jan, 2007 Compared with the relation from Bugaev et al, Phys. Rev. D58, 05401 (1998)
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
NEMO Phase-2
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
STATUS - 100 km electro-optical cable (>50 kW,
20 fibres) deployed in July 2007 - DC/DC power converter built by Alcatel
tested and working; installation in july 2009
- On-shore laboratory (1000 m2) inside the harbour area of Portopalo completed
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
The Alcatel DC/DC system
System based on an innovative 10 kW DC/DC converter specifically designed by Alcatel for deep-sea applications A final prototype of the DC/DC converter has been tested at full load in realistic conditions
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Test of the DC/DC converter
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Upgrades in the tower design
DC power system to comply with the feeding system provided by Alcatel
Data transmission system
Segmented electro-optical backbone
Acoustic system integrating both positioning and acoustic detection systems
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
KM3NeT
European Consortium involving 40 Institutes from 10 countries
Design Study project (FP6) • Define the technologies for the contruction of the km3
Preparatory Phase project (FP7) • Define the governance, legal and financial issues and prepare plans for
construction of the Research Infrastructure
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Convergence in KM3NeT
Three full designs are presently considered in KM3NeT
The final choice will be based on detector sensitivity, cost and reliability
One of the designs, developed by INFN and IN2P3, is largely based on the experience and technical solutions developed in NEMO and ANTARES • Tower with horizontal extent • Packable structure for integration and deployment with unfurling
on the seabed • Synchronous all-data-to-shore readout • DC power feeding system
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
New data daisy chain data transmission system
The link is bidirectional with asymmetric data rates: • Up-going link @163.84 Mb/s for timing
and slow control • Down-going link @1.18 Gb/s for
physics data and control
All nodes are identical The system can be implemented using either a fibre or a copper backbone
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Op#calbackbone
Op#calconnector
Electricalconnectors
Electricalbackbone
Hidrophoneconnector
ElectricalconectortoOMFloorelectronicsmodule
Op#calmodules
Op#calmodules
Floorelectronicsmodule
“DaisyChain”connec/ons
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Power distribution network
Electro‐Op#calCable
100Km
x17÷24 x5...
10KVdc
Lmax1500m
375Vdc...
Lmax250mDU1
DU2
DU5
POWER BUDGET
N° DU 84 120
Power per DU 300 W
DUs total power 25,2 kW 36 kW
Cable Losses < 4% 1 kW 1,5 kW
Cable voltage drops% < 4%
Total Power off-shore 26,2 kW 37,5 kW
MVC losses (η=80%) 6,6 kW 9,4 kW
Main Cable losses 1,7 kW 3,5
TOTAL POWER LOSSES 27% 28%
POWER ON SHORE 34,5 kW 50,4 kW
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
One idea for the seabed layout and cable network
PrimaryJB
SecondaryJB
DU
MaincableCablePJB‐SJBCableSJB‐DU
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Optical network to shore
PJB
**
*
......
*
*
......
17
... ...
*
*
*
**
*
...
1
8...
*
*
......
1
8
1
8
1
8
SJB17
SJB24
SJB1
SJB8
DWDMmux
demuxSta#on
MEOC
bandmux‐demux
...
...
*
*
*
17
2424
17
24
17
24
DU1
DU5
...
DU116
DU120
...
SHORE SUBSEA
...
...
...
...
1B
119B120B
...
1
2324
1A
119A120A
Ring topology based on circulators: doubled offshore and onshore to achieve 100% redundancy; 1 ring can support as many DUs as fiber bandwidth allows; Standard ITU frequency grids accommodate up to 60 ÷132 colors (100 GHz or 50 GHz grid spacing) 3 rings are needed to transport 120 DUs; 6 fibers of the Main Electro Optical Cable are used to setup the 3 rings between shore and subsea;
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Near future plans
Test of a “mechanical” tower in may-june 2009 to validate the structure and the new buoy design at 3500 m depth
Building of a fully equipped tower with a reduced number of floors to test the technological solutions proposed in KM3NeT (in collaboration with the IN2P3 groups) to be deployed in spring 2010
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
Conclusions …
In a ten year long activity NEMO has provided significant contributions towards the km3 detector • Identification of an optimal deep-sea site • Development and test of technologies for the
telescope construction
The NEMO collaboration is presently taking part in the KM3NeT EU consortium
P. Piattelli RICAP09, Villa Mondragone, 14-5-2009
… and outlook
For the construction of the KM3NeT european Research Infrastructure a multi-site option is also being considered
This options fits a funding scheme in which most of the funding will come on a regional basis
The assessment of the single vs multi-site option will be done within the Preparatory Phase project, but preliminary results indicate that a multi-site telescope has at least the same sensitivity than a single one
Initiatiatives to get fundings are under way in several countries (France, Greece, Italy, The Netherlands)
In Italy the Sicilian Regional Government has proposed the funding of a km3 size detector on national funds for the less developed regions